Incubator curriculum

Dr. Franklin O. Chukwuma Alcorn State University Extension Program Alcorn State, MS 39096-7500

HORTICULTURE CURRICULUM

Unit I: Soil Objective: To provide the reader some information on soils and how it provides vital nutrients for plant growth.

Session 1: Soil and Its Components Session 2: Importance of Soil Testing Session 3: Soil Sampling Methods Unit II: Fertilizer (Nutrients) Objective: To provide the reader with information on how fertilizers can enrich soils and increase plant growth.

Session 1: Importance of Fertilizers Session 2: Major Chemical Elements Session 3: Soil pH Unit III: Vegetable Production Objective: To provide the reader information on proper crop production techniques.

Session 1: Site Selection Session 2: Planting Vegetables Session 3: Harvesting Vegetables Unit IV: Weed and Insect Control Methods Objective: To provide readers with information on ways to control weeds and insect pests.

Session 1: Destructive Insects Session 2: Pest Management Session 3: Integrated Pest Management Unit V: Disease Control Objective: To provide readers with information on ways to control weeds and insect pests.

Session 1: Types of Diseases Session 2: Controlling Diseases

Unit VI: Water Resources

Objective: To provide readers with information on water resources and how these resources can be affected by human activities.

Session 1: Essentials of Water Session 2: Components of Water Session 3: Contamination of Water Unit VII: Safety Objective: To provide readers with information on safe handling of farm and garden chemicals.

Session 1: Importance of Safe Chemical Handling Session 2: Correct Methods for Handling Chemicals

INTRODUCTION The vegetable industry is a dynamic one. Cropping practices, regardless of commodity, change continually, incorporating innovations by growers and new technology supplied by biochemists, physiologists, geneticists, engineers, economists, and other at an accelerating rate. It is difficult to partition these technologies within a textbook, for they represent inputs within highly integrated vegetable production systems. A given technology also may have a different purpose for different crops in different production areas.

Therefore, educators and farmers must recognize that techniques and skills alone are insufficient to maintain a progressive business. A broad understanding of basic sciences and of the economics of the marketplace is essential if one is to remain progressive. This text is directed toward the agricultural educators who have acquired an understanding of crop production. The first portion of this book is devoted to resources that are fundamental to successful vegetable production and to the general vegetable management systems that have evolved to integrate those resources.

We would be presumptuous if we thought that this one publication held all the answers.

It does not. It is our hope, however, that it will serve as a starting place for other programs. We hope it will be an inspiration to others – an inspiration to take up the twin challenges of first developing an acceptable or appropriate technology and then developing the infrastructure and teaching programs to transfer this technology to where it is needed.

The time is short and we must be successful. The “daily bread� of billions now present and to follow depends upon our success.

HORTICULTURE CURRICULUM

Unit I SOIL Unit I: To provide the reader information on soils and how it provides vital nutrients for plant growth.

After reviewing this unit, the learner will be able to:  explain the components of soil  explain why plants need soil  describes the functions of soil  explain the moisture retention capabilities of the three primary soil particles  list how three soil layers are formed  describe ways to enrich soil What is soil? Soil, the foundation for life on Earth is the outermost layer of our planet.

Soil needs to be rich and fertile if plants are to grow healthy and strong. Soil has varying amounts of organic matter (living and dead organisms), minerals, and nutrients.

Topsoil is the most productive soil layer. Plants need support, oxygen, ions, and liquid to survive. There are plants which live in water or other conditions without soil, and there is an agricultural production process, hydroponic production, which makes it possible to grow plants without soil. But the vast majority of plants which humanity depends for food and fiber depend on soil. The underground environment for the roots of plants living in adequately watered garden soil contains nearly 50 percent solids, 25 percent air, and 25 percent water. Through their roots, plants rake in air (oxygen), water (moisture), and nutrients (minerals). Plants use these vital elements to survive.

Soil? How do soils from? Soils are formed by a slow weathering process that takes place above and below the Earth’s surface. This weathering process begins with this physical breakdown and chemical decomposition of rock. Above ground, weathering can start with wind and rain blowing against mountains. Boulders become loosened, and freezing rain cracks the smaller boulders into even smaller pieces.

During decomposition, both above and below the ground, rock chemically reacts with water and other acidic solutions to produce “rotten” rock that falls apart more easily.

Chemicals released during rock decomposition are sources of the nutrients that help plants grow. The list of nutrient includes nitrogen (N), phosphorous (P), potassium (K), and many others.

Although wind and water reduce rock into sand, silt, and clay, these particles alone do not produce fertile soil. The particles mix with organic matter – the decayed remains of plants and animals. Decay keeps the soil fertile, able to nourish plant growth, by recycling nutrients. Soil is a temporary storehouse for nutrients.

Soil. Do soils have distinct layers?

Nearly all soil develops three distinct layers called “horizons.” Separate layers of a soil differ from one another in various physical and chemical characteristics.

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Top layers of soil (A horizon) consist mostly of organic material. Subsoil layers (B horizon) have many fine clay particles. The lower subsoil (C horizon) contains partially decomposed pieces of solid rock. Beneath the three layers is the parent rock from which the soil originated.

Rain, decay, and living organisms form the web of life that produces fertile soil. Thus, fertile soil is a renewable resource. Litter and surface soils are full of microscopic life, such as bacteria and fungi. When a leaf falls or a field mouse dies, living worms and bacteria feed on those organisms and make them part of the soil.

Soil. What determines soil structure and classification? Small particles of sand, silt, and clay give soil its structure. A sand particle is much larger than a silt particle, while clay particles are, by far, the smallest.

The ratio of these particles is the key to soil classification. Loam (the most desirable soil) is a mixture of nearly equal parts of sand, silt and clay. If the soil has more silt than loam, it is silty loam; more sand than clay, it is sandy clay; more clay than loam, it is clay-like loam, and so forth.

TEXTURE Texture is an important soil property because it is closely related to many aspects of soil behavior. Soil texture refers to the percentage by weight of sand, silt, and clay in a soil.

The ease of tilling and plant root development within the soil is both influenced by soil texture. Texture affects the amount of air and water a soil will hold and the rate of water movement through the soil. Plant nutrient supplies are also affected by soil texture.

Most of the soil layers provide homes for a variety of animals: ants, beetles, grubs, spiders, mites, springtails, millipedes, snails, worms, and small rodents such as mice and shrews. As these animals burrow and tunnel beneath the soil, they mix and break soil into tiny fragments. Their passages also allow air, water and nutrients to penetrate beneath the soil surface.

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Water-Holding Capacity Soil. Why is soil classification (ratio of clay, silt, and sand) important?

Different types of soil hold different amounts of water, minerals, and air. Sandy soils drain well because they have large air spaces.  Sandy soils drain well because they have large air spaces. Water is lost more quickly from the large spaces between sand particles, as the force of gravity drains the water out. Also, sandy soils have little capacity to hold plant growth minerals. 

Clay soils have poor drainage and air holding spaces. Because of this, clay and other heavy soils often hold more water than is good for plant growth. On the other hand, clay soils may be thicker in nutrients, because they can hold plant minerals more effectively than soils composed of larger particles.

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Silt prevents water and minerals from leaching, or draining out of the soil.

Therefore, farmers and gardeners need to know to what kind of soil is present. For example, sandy soils require less fertilizer and more frequent application of water than clay soils.

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SOIL ENRICHMENT Soil. How can people enrich soil? The composition, moisture-holding capacity, drainage, and fertility of soil can be changed by using soil enrichers. Adding organic matter improves the water-holding capacity of soils. Animal manure, peat moss, and sawdust are good sources of organic matter. Chemical or natural fertilizers can also be used to provide important plant nutrients.

Spreading mulches, such as wood chips and straw, on the soil surface helps to retain soil moisture, reduces runoff, and allows more rainwater to drain into the soil. Mulches keep soil cooler by reducing evaporation loss.

All crops are required particular soil conditions for optimal yields. One of the best ways to evaluate the soil of a potential site is by performing a soil test. Soil testing can reveal the percentage of organic matter, pH, and amount of available nutrients in the soil. A soil test is a good guide for determining the proper amount of fertilizer and soil amendments for the site. Soil testing should be done when selecting a site and also should be performed periodically to monitor conditions and diagnose any problems.

Amending the soil before crops are planted can help save time and money in the long run. A soil test also measures soil pH, humic matter and exchangeable acidity. These analyses indicate whether lime is needed and, if so, how much to apply.

IMPORTANCE OF SOIL TEST Soil Test A soil test is a process by which elements (phosphorous, potassium, calcium, magnesium, sodium, sulfur, manganese, copper and zinc) are chemically removed from the soil and measured for their “plant available� content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizer that is recommended. A soil test also measures soil pH, humic matter and exchangeable acidity. These analyses indicate whether lime is needed and, if so, how much to apply.

All crops require particular soil conditions for optimal yields. One of the best ways to evaluate the soil of a potential site is by performing a soil test. Soil testing can reveal the percentage of organic matter, pH, and amount of available nutrients in the soil. A soil test is a good guide for determining the proper amount of fertilizer and soil amendments for the site. Soil testing should be done when selecting a site and also should be performed periodically to monitor conditions and diagnose any problems.

Amending the soil before crops are planted can help save time and money in the long run.

Why Do You Need a Soil Test?

Encourages plant growth by providing the best lime and fertilizer recommendations.

When growers guess about the need for lime or fertilizers, too little or too much is likely to be applied. By using a soil test report, the grower does not need to guess.

For Example: When applying too much lime, soil pH may rise above the needed level, which causes nutrients such as iron, manganese, boron, copper and zinc to become less available to plants. It is also common to see homeowners purchase one bag of lime when they purchase one bag of fertilizer.

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Based on an average lawn size of 5000 square feet, one bag of fertilizer may be enough. Applying one bag of lime over 5000 square feet, however, will have little effect on soil pH. 

Promotes environmental quality. When gardeners apply only as much fertilizer as is necessary, nutrient runoff into surface or ground water is minimized and natural resources are conserved.

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Soil test saves money that might otherwise be spent on unneeded lime and fertilizer. A soil sample must be taken at the right time and in the right way. The tools used, the area sampled, the depth and the correct mix of the sample, the information provided, and packaging all influence quality of the sample.

Soil sampling method  Take a soil sample a few months before starting any new landscaping – whether you’re laying sod, starting a vegetable garden, putting in a flower bed, or planting perennials. If the soil test report recommends lime, you will have enough time to apply it and have it adjust the soil pH before you plant. 

Sample established areas – lawns, trees, shrubbery, and other perennials – once every three or four years. You can sample at any time of year; however, mid-August through mid-September is an ideal time to take samples for cool-season grasses, such as fescue, bluegrass, and ryegrass. By sampling at this time, you can be ready to apply lime in the fall.

For areas recently limed or fertilized, delay sampling at least six to eight weeks.  Use a soil probe, spade, hand garden trowel, or shovel to collect samples. Do not use brass, bronze, or galvanized tools because they will contaminate samples with copper and/or zinc. 

Mix samples in a clean, plastic bucket. If the bucket has been used to hold fertilizer or other chemicals, wash it thoroughly before using it for soil samples.

Sample each unique area separately.  Each sample should represent only one soil type or area – for example, a lawn, vegetable garden or perennial landscaped area.

For each unique area, take at least six to eight sub samples and combine them to make one sample. If one area of your yard seems healthy and another has bare or yellow areas, sample healthy and unhealthy areas separately even if both are lawn grasses or flower gardens, etc.

Take a soil core to the appropriate depth.  For lawns, sample to a depth of four inches, excluding any turf thatch. 

For vegetable and flower gardens, sample to the depth that you plan to mix in lime or fertilizer, usually four to six inches.

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For shrubbery, remove any mulch or surface debris, then sample to a depth of four to six inches around the base of plants. Avoid zones where lime or fertilizer has been recently applied. Farmers and gardeners needs to know what kind of soil is present. For example, sandy soils require less fertilizer and more frequent application of water than clay soils.

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Place all the sub samples for one unique area in a plastic bucket and mix thoroughly.

Use the mixture in the bucket to fill a soil sample box about two-thirds full. Look for the fill line on the box.

Fill out an information sheet and label the sample box completely.  Get your sample boxes and information sheets from Cooperative Extension offices, agribusinesses, regional agronomists, or the Agronomic Division laboratory. Use permanent ink or pencil to fill out forms and label boxes.

Package the sample appropriately.  Put the soil mixture in the sample box. Do not tape the box or put soil in a plastic bag. If you are sending several sample boxes through the mail, pack them carefully in a sturdy container.

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ACTIVITIES Soil Sleuths What to Expect Participants will explore qualities of different soils using their senses of touch, smell, hearing and sight.

Materials Needed  Soil samples  Measuring cups  Sealable sandwich bags  Paper lunch bags  Index cards  Paper  Pencils  Watch with a second hand or stopwatch  Construction Paper Getting Ready  Review Nitty Gritty background information and discuss with the group. 

Have participants take the Soil pre-test found in What’s the Score?

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You will need to obtain one-cup soil samples from at least four locations (schoolyard, playground, sandbox, garden, etc.). Obtain your soil samples at least two inches below the surface. Do not filter the soil, but remove any trash that may be found in your sample. Place each soil sample in a separate sealable bag. Label the type of soil collected in each bag and where it was found.

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Set up an observation station for each soil sample collected. At each station place a bag of soil, one paper bag, a stack of index cards (at least one per team member), pencils, and one sheet of construction paper.

Listen Up! Soil is composed of living and non-living matter. It helps provide plants with support, nutrients, water and air. However, soil does not provide plants any food substances; plants make their own food with their leaf systems. Soil takes many years to develop. It can take as long as 20,000 years to make one inch of topsoil because rocks must be broken down into smaller particles. Soil is formed once living and non-living components interact, combine and change.

Soil particles range in size from large sand to fine clay particles. The proportion of these particles determines the amount of air, water, and nutrients available in the soil.

Organic matter is another important component of soil. Organic matter can come from the remains and waste products of living things – both plants and animals.

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How many senses do we have? Do we use all of them to describe something to another person? Let’s explore the soil in the containers. In small groups, you will go to every station and use your senses to explore all of the soil samples. Time will be allotted for all of you to rotate among the stations and examine the types of soils at all of them.

Activity 1. Divide the group into as many small teams as there are soil samples. Explain that each team will spend a few minutes at all of the stations exploring the soil.

2. When you say “Start,” the teams will have one minute to examine the soil at their station, write at least one descriptive word about the soil on an index card and place the card into the bag.

3. When you say “Change,” they will rotate to the next station. Have them to repeat Step 2 until they have visited all of the stations.

4. When everyone is finished say “Stop.” Give each team one bag of the descriptive words.

5. Explain that each team will use the words in their bag to write a report to people from another planet who wish to know what the soil is like on Earth.

6. Ask a volunteer from each team to read their letter.

Share  What senses did you use to explore the soils?  What are some words you used to describe what you saw, felt, smelled, or heard?  How are the soils similar? Different?

Process  Did everyone use the same words to describe the different soils?  How can you identify which soils is sand, clay or loam by using your senses?  How do you think different layers of soil are formed?  Which soils felt as if they had a mixture of particles?

Generalize  What other objects can be identified using your senses?  What experiments using the scientific method can you do to discover something about the importance of soil particle size?  Why is it important to understand diversity among both living and non-living things?

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Unit II Nutrient Cycles (Fertilizer) Objective: To provide students with background information on how fertilizers can enrich soils and increase plant growth.

After reviewing this unit, the student will be able to:  explain why plants need fertilizers  describe the major elements found in plants  explain the difference between organic and inorganic fertilizers  describe the symptoms of plants having insufficient levels of nitrogen, phosphorous, and potassium.

Fertilizers are often called “plant food,” but it is incorrect to label fertilizers as food.

Plant roots absorb three vital nutrients: nitrogen, phosphorous, and potassium from the soil. Plants use these nutrients, along with several others, in a food-making process called photosynthesis. During this process, plants build all the molecules they need for energy, growth, and reproduction Seventeen chemical elements are known to be important to a plant’s growth and survival. The seventeen chemical elements are divided into two main groups: nonmineral and mineral.

The Non-Mineral Nutrients are hydrogen (H), oxygen (O), & carbon (C).

In a process called photosynthesis, plants use energy from the sun to change carbon dioxide (CO2 – carbon and oxygen) and water (H2O – hydrogen and oxygen) into starches and sugars. These starches and sugars are the plant’s food.

Photosynthesis means “making things with light”.  Since plants get carbon, hydrogen, and oxygen from the air and water, there is little farmers and gardeners can do to control how much of these nutrients a plant can use.

The 14 mineral nutrients, which come from the soil, are dissolved in water and absorbed through a plant’s roots. There are not always enough of these nutrients in the soil for a plant to grow healthy. This is why many farmers and gardeners use fertilizers to add the nutrients to the soil.

The mineral nutrients are divided into two groups:  Macronutrients  Micronutrients Macronutrients Macronutrients can be broken into two more groups:  Primary  Secondary nutrients 9

The primary nutrients are nitrogen (N), phosphorous (P), and potassium (K). These major nutrients usually are lacking from the soil first because plants use large amounts for their growth and survival.

The secondary nutrients are calcium (Ca), magnesium (Mg), and sulfur (S). There are usually enough of these nutrients in the soil so fertilization is not always needed.

Also, large amounts of Calcium and Magnesium are added when lime is applied to acidic soils. Sulfur is usually found in sufficient amounts from the slow decomposition of soil organic matter, an important reason for not throwing out grass clippings and leaves.

Micronutrients Micronutrients are those elements essential for plant growth which are needed in only very small (micro) quantities. These elements are sometimes called minor elements or trace elements, but use of the term micronutrient is encouraged by the American Society of Agronomy and the Soil Science Society of America. The micronutrients are boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn). Recycling organic matter such as grass clippings and tree leaves is an excellent way of providing micronutrients (as well as macronutrients) to growing plants.

What do the letters and numbers on a fertilizer container represent?

Letters and numbers (always listed in the same order) on fertilizer containers show a guaranteed analysis of nitrogen (N), phosphorus (P), and potassium (K) found in the container. The numbers show the percentage by volume of N-P-K found in the fertilizer.

For example, if the container is a hundred-pound bag of fertilizer bearing the three numbers 10-10-10, it contains 10 percent nitrogen, 10 percent phosphorous, and 10 percent potassium. The other 70 percent is filler (inert) material.

Fertilizer: Do we need fertilizers to grow food crops?

Commercial growers must control the plant’s environment to obtain the optimum (best) return for their investments. This often involves improving soil condition through the addition of fertilizer. Fertilizer allows food producers to grow the same crop year after year in the same field.

Fertilizer: Why are fertilizers used in some locations and not in other places?

A fertilizer is a material that contains one or more of the mineral nutrients required for plant growth. Fertilizers supply additional nutrients to the soil.

Natural ecosystems can produce enough mineral nutrients to sustain themselves because nutrients accumulate in soil from the decay of animal and vegetable material.

The soil in many other locations is deficient in nitrogen, phosphorous, potassium, and other nutrients. That soil may need enrichment before quality crops will grow there.

Fertilizer: Can natural (organic) fertilizers replace inorganic fertilizers?

Manufactured or mined fertilizers are inorganic. Organic fertilizers include animal waste (manure), bone meal, blood meal, and many other natural by-products. The mineral nutrients in both types of fertilizers are the same. Plants do not use all of the fertilizer applies to the soil.

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Rain can cause the surplus fertilizer (agriculture runoff) to leach into underground water supplies (aquifers) and into surface streams and lakes. Sometimes, livestock waste leaches into nearby water supplies, too. Rain runoff from both sources may create longand short-term problems for humans.

Fertilizer: Why and how do plants use nitrogen (N)?

Nitrogen has the most noticeable effect on plants. It stimulates aboveground growth, causing plants to produce soft, tender growth and dark green leaves. The tender growth makes the plant taste better. Nitrogen deficiency results in a plant being stunted and pale-green or yellow in color. Nitrogen deficiencies are often noticed when the leaves of plants turn light green or yellow before dropping off.

Too much nitrogen can damage plants by:  Lowering their resistance to disease  Weakening stem growth  Causing fruits to be too soft to ship  Increasing chances for winter damage due to a delayed hardness of plant tissue.

Fertilizer: Why and how plants use phosphorous (P)?

Phosphorous, nicknamed “the flower-maker,” is present to some extent in all soil.

Phosphorous takes longer than nitrogen to leach from soil particles.  Phosphorous  Stimulates root growth  Increases the plant’s resistance to disease  Encourages plant cell division  Starts flower and fruit formation  Accelerates plant maturity by offsetting the quick growth response caused by nitrogen.

Phosphorous deficiencies generally appear as a purple color on the undersurface of leaves. Such a deficiency causes reduced root, flower, fruit, and seed production.

These plants also develop a greater susceptibility to cold injury and plant diseases.

Fertilizer: Why and how do plants use potassium (K)?  Potassium, nicknamed “the fruit-maker,”:  Stimulates plant starch formation  Increases tuber development  Hastens chlorophyll formation  Helps a plant to efficiently use carbon dioxide, nitrogen and phosphorus.

Plants suffering from a lack of potassium fail to grow properly. They have weak stems, and if they bear flowers, the blossoms are small and pale. The leaves on potassiumdeficient plants usually appear dry and scorched on the edges with irregular yellow areas on the surface.

Calcium  Calcium, an essential part of plant cell wall structure, provides for normal transport and retention of other elements as well as strength in the plant. It is also thought to counteract the effect of alkali salts and organic acids within a plant.

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11 Sources of calcium are dolomitic lime, gypsum, and superphosphate.

Magnesium Soil minerals, organic material, fertilizers, and dolomitic limestones are sources of magnesium for plants.  Magnesium is part of the chlorophyll in all green plant and essential for photosynthesis. It also helps activate many plant enzymes needed for growth.  Essential plant food for production of protein.  Promotes activity and development of enzymes and vitamins.  Helps in chlorophyll formation.  Improves root growth and seed production.  Helps with vigorous plant growth and resistance to cold.

Sulfur Sulfur may be supplied to the soil from rainwater. It is also added in some fertilizers as an impurity, especially the lower grade fertilizers. The use of gypsum also increases soil sulfur levels.

Micronutrients  Helps in the use of nutrients and regulates other nutrients.  Aids production of sugar and carbohydrates.  Essential for seed and fruit development.

Organic matter Organic matter is an important factor in soil evaluation because it supplies most of the nitrogen that is naturally present in the soil and may account for about half of the phosphorous. It also improves soil structure and aids in good soil aeration and healthy root development.

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Soil pH Soil pH (a measure of the acidity or alkalinity of the soil)  Soil pH is one of the most important soil properties that affect the availability of nutrients.

Fertilizer: How does pH level affect mineral nutrient availability in soil?

Soil acidity (pH) has a strong influence on the availability of plant mineral nutrients.

Most plants grow best in soil with a pH of from 6.0 to 7.0. For instance, the pH range for cabbage is 6.0 – 7.5; carrots, 5.5 – 7.0; onions, 6.0 – 7.0; and radishes, 6.0 – 7.0. A pH of 7.0 is neutral; that is, the soil is neither acidic nor alkaline (basic). On the pH scale of 1 to 14, values lower than 7.0 show acid soils and value higher than 7.0 show alkaline soils. Different substances may be added to soils either lower or raise pH levels. pH Scale

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Macronutrients tend to be less available in soils with low pH. Micronutrients tend to be less available in soils with high pH.

Lime can be added to the soil to make it less sour (acid) and also supplies calcium and magnesium for plants to use. Lime also raises the pH to the desired range of 6.0 to 6.5.

In this pH range, nutrients are more readily available to plants, and microbial populations in the soil increase. Microbes convert nitrogen and sulfur to forms that plants can use. Lime also enhances the physical properties of the soil that promote water and air movement.

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A BALANCING ACT What to Expect Participants will learn about plant competition.

Materials Needed      

Three poster boards (green, yellow and red) Pencils Notebooks Scissors Rulers Storage container

Getting Ready  Review Nutrient Cycles Background information and discuss with the group.  Have participants take the Fertilizer pre-test found in What’s the Score?  Cut 2” x 2” squares of each color of poster board (allow at least two squares of each color per youth). Mix the squares and place them in the storage container.

Listen Up! Plants cannot live on sunlight, carbon dioxide and water alone; they also require a combination of nutrients. Because the physical condition of some soils may be poor, we sometimes add fertilizer. A fertilizer contains one or more of the nutrients required to promote plant growth. Plant roots absorb three vital nutrients from the soil: nitrogen, phosphorous, and potassium. A soil test indicates how much fertilizer a garden’s soil needs. Let’s go outside and take a look at how plants often compete with weeds and each other for these vital nutrients.

Activity 

Select an appropriate indoor or outdoor location and determine the boundaries of a make-believe garden.

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Divide the group by having participants count off one-two. The ones will be weeds and the twos vegetables.

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Allow the vegetables time to line up in rows evenly spaced in the garden.

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Ask the weeds to randomly fill in spaces among the vegetables.

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Tell the group that they will be playing a game to gain a better understanding of plant competition. The object of the game is for the weeds and vegetables to gather as many squares as they can.

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Remind the participants that all plants are anchored firmly in the ground and cannot move from one location to another by themselves. They are not allowed to move their feet as they reach down to pick up the nutrients. If they do, they will be disqualified.

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Scatter the 2” x 2” squares on the ground around the weeds and vegetables.

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Give a signal to start the first round.

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Allow the vegetables and weeds to gather as many nutrients as possible in one 10 second rounds.

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Have participants record the number of each nutrient they gathered.

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Collect the nutrients and repeat steps 7-10 two more rounds, recording and comparing the results after each round.

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Explain that each colored square represents a plant nutrient. Green represents nitrogen; yellow represents potassium; and red represents phosphorous. If a vegetable or a weed did not pick up at least two of each nutrient on the third round, they “die” and must step back from the garden.

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Repeat a couple more rounds, recording and comparing the results each time.

Share   

How did you feel about being a weed? A vegetable?

How many of each nutrient did you get?

What kept you from getting a higher number of each nutrient?

Process    

Who got more of each nutrient – the vegetables or the weeds? Why? Did any plants die because they did not get any nutrients?

Why is it important to know that weeds and vegetables compete in gardens?

Why is it important to know the mineral content of soil?

Generalize  What are some resources for which people compete?  How do you feel when you are faced with competition?  How well do you perform under pressure?  What happens when animals compete for resources?

Apply    

What can be done to reduce pressure during competition?

How will you act differently in the future when you are in a competitive situation?

How can you explain competition to someone else?

How will you apply what you have learned in this activity in your Down-to-Earth garden?

Want To Do More?

Have the participant:

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Visit a local garden center and compare the N-K-P composition of commercial fertilizers.

15 Contact their county Extension Horticulture Agent to learn how to identify symptoms of plants that have insufficient levels of nitrogen, potassium and phosphorous.

Investigate and write about a career in landscape design.

Test Your Knowledge 

Have youth take the Fertilizer post-test found in What’s the Score?

Listen Up! All plants need nutrients to grow. The three major plant nutrients are nitrogen (N), phosphorous (P), and potassium (K). These nutrients, along with water, are absorbed through their root system. Nitrogen helps the plant to have leafy, green growth.

Phosphorous promotes root and fruit development.

Potassium is important to many plant functions including stimulation of plant starch, and formation and development of tubers. Sometimes, nutrients are needed to improve soil fertility. There are, however, natural sources of fertilizers such as animal waste, dried blood, and bone meal. Most soils require the addition of fertilizer to promote plant growth.

Once fertilizers break down in the soil, water helps to transport the nutrients up the plant stems to its leaves and petals. In this activity, you will do an experiment to see how these nutrients travel up the stalk of a vegetable.

Activity       

Explain that each participant will conduct their own experiment.

Fill each cup or glass half full of water.

Add four spoonfuls of sugar to one cup and label it with an “SU” for sugar. Add four spoonfuls of salt to one cup and label it with “SA” for salt. Do not add anything to the third cup. Label it with “H2O” for water.

Add 15 drops of red or blue food coloring to each cup. Stir the water with a spoon until the sugar and salt dissolve.

Take a stalk of celery and carefully break off the lower end or snip it off with the kitchen scissors. Put one stalk of celery in each cup, and leave the celery in the water for 24 hours.

After 24 hours, look at the celery to see whether or not there has been a color change. Record your observations. Repeat after 24 more hours.

Taste the leaves form each celery stalk. Record your findings.

Share    

What did you observe after you added the sugar, salt and food coloring to the water?

How did the celery stalk and leaves look after 24 hours? After 48 hours?

How did the celery leaves taste after 48 hours?

What did you like the most about this activity? The least?

Process 

Why is it important for some solids to dissolve in liquids?

 

How did the sugar, salt and water go up the celery stalks?

Why did you cut the ends of the celery stalks before placing them into the cups?

16

Generalize    

What actions cause solids to dissolve in liquids?

How are nutrients from food substances absorbed into our bodies?

Why is it sometimes necessary to supplement your diet with nutrients?

What happens to living things that do not receive proper nutrition?

Apply   

How will you explain to someone about the need for proper nutrition?

You have probably heard someone say, “You should eat all your vegetables.” Do you agree? Why or why not?

How will you apply what you have learned in this activity in your Down-to-Earth garden?

Want To Do More?

Have the participant:  Build a compost pile and use the waste to fertilize their Down-to-Earth garden.  Test the hypothesis: organic fertilizers produce a greater volume of vegetables than inorganic fertilizers.  Investigate and write about a career in soil and crop management.

Test Your Knowledge 

Have youth take the Fertilizer post-test found in What’s the Score? if not taken in the previous activity.

17

Unit III Vegetable Production Objective: To provide reader with information on proper crop production techniques.

After reviewing this unit, the reader will be able to:  Determine the suitable site for growing vegetables  Determine proper planting methods  Determine proper harvesting methods Site Selection Before deciding what to plant, it is important to evaluate the prospective site to determine if it is suitable. Several key environmental and non-environmental elements must be assessed. Evaluating a site requires forethought and effort, and long-term goals should be kept in mind to reach the desired results. Carefully considering each of the essential factors before selecting a site can help avoid problems in the future.

Topography Topography refers to the relative positions and elevations of the natural and fabricated features that describe the surface of an area. Topography affects soil condition and what types of plant can grow well in the area and also is a significant factor in regard to accessibility for machinery.

Topography determines how wind and water move toward, over, and away from an area. This interaction between the topography and the wind and water significantly affects the soil erosion, soil drainage, and water-holding capacity of the site. Soils in low areas tend to be moist and poorly drained while soils in more sloping areas tend to be drier and well drained. On steeper slopes, topsoil may erode, exposing the subsoil or parent material.

To some extent, topography explains why similar enterprises are located in similar regions. Whatever type of enterprise, the topography must be able to support the operation’s activities profitably.

Accessibility Accessibility refers to how readily a site can be reached and used. It should be easy to get into and out of the area with all the equipment and supplies needed to plant, maintain, and harvest the crop. There should be access to any utilities that are needed, such as water and electricity. Consideration should also be given to where roads currently are and where they will need to be built on the property to provide access.

Traditionally, it was primarily the owners, operators, and workers who needed access to the farm.

However, producers who are considering an operation such as a pick-your-own or CSA farm must also determine whether the site is accessible to the public. If consumers will be frequenting the farm, it is important that the farm have sufficient parking, clear roads and traits, and barrier-free access to all services and facilities.

18 Climate Another environmental factor to consider when selecting a site is the climate. Climate is all the atmospheric influences, usually considered over a number of years that combine to influence the land forms, soils, vegetation, and land use of a region. The principal atmospheric influences are temperature, moisture, wind, pressure and evaporation.

The climate of the area will help determine that plants will thrive during the growing season.

Climate and region will determine the frost dates of the area. The frost dates are the estimated dates of the last frost in spring and the first frost in fall. The time between the frost dates is the growing season in which plant can reach maturity and produce fruits and vegetables that are ready to harvest. Frost dates are determined by the U.S. Department of Agriculture based on historical data. Because the dates are estimates, there is always a chance of unexpected early or late frost.

Utilities A site should also be evaluated for the ease with which utilities and services can be provided. The distance to services and utilities should be considered because it will affect the cost of bringing them to the site. Water should be readily available and plentiful, and water quality should also be considered. Depending on what equipment will be used, electricity might also be needed.

Zoning Zoning controls the physical development of land and dictates the kinds of uses allowed on individual properties. Zoning laws determine the areas in which residential, industrial, recreational, and commercial activities can occur. Local governments commonly control zoning. Prior to starting production, be sure to check with the local zoning board about the regulations concerning the specific site.

Labor The type of labor needed will depend greatly on the type, size, and scale of production being considered. The availability of a labor force in the area should also be investigated. Depending on the crop and production scale, labor may be automated or done by hand. Hand labor is work done by people working manually with the crops.

Automated labor is done by people operating machines.

Planting Consideration The term vegetable is generally used to refer to the edible portion of herbaceous (nonwoody) plants – the roots, stems, leaves, flowers, or fruit.

There are many different varieties and hybrids of most types of vegetables. A variety is a plant that occurs naturally or through cultivation and differs from other members of its species by one or more characteristics. A hybrid is a plant that results from interbreeding two distinct cultivars, varieties, or species. Varieties and hybrids offer certain desirable characteristics, such as good size, flavor, and appearance and

resistance to certain pests and diseases. Consideration must be given to what varieties and hybrids are appropriate for a particular area and climate when choosing vegetables to grow.

19 Cool Season Crops A cool season crop is a crop that grows best during the cool temperatures of fall and spring. Cool season crop prefer temperatures between 50°F and 70°F. These include beets, carrots, potatoes, cabbage, cauliflower, and many others. Cool season crops are very tolerant of cold weather and can usually stand a light frost.

Two primary types of cool season crops are root crops and surface crops. Root crops are vegetables that are primarily cultivated for their edible roots, tubers, or modified stems, which grow below ground. Surface crops are grown for edible parts – leaves, flowers, and “fruits” – that grow above ground.

Warm Season Crops Warm season crops are crops that are severely harmed by frost and do not grow will until the temperature is at or above 70°F. Examples of warm season crops include tomatoes, eggplants, and corn. Warm season crops should only be planted when soil temperatures are warm enough to induce sprouting.

Long Season Crops Long season crops are vegetables that require a relatively long growing season to mature compared to other plants. Examples of long season crops include pumpkins, gourds, and watermelons.

Planting Dig in for the Garden Season Garden soil can be plowed, tilled or spaded in the spring or fall. Don’t work the garden when the soil is too wet. One test is to squeeze a handful of soil. It should not be sticky and should form a ball that will crumble easily.

Fertilizer may be applied before plowing. Turn over the ground to a depth of about 6 to 8 inches. If added after plowing, work in the fertilizer by raking it into the soil to a 2- to 4-inch depth. Rake the soil just before planting to prevent the weeds from coming up before the vegetables.

Success Starts with Planting The success of your garden depends on three factors. Vegetables must be planted at the right time, at the right depth and at the correct distance apart.

The planting time depends on the hardiness of the vegetables and the climate in your area. Some vegetables can withstand frost, others prefer warm weather. When purchasing seeds, be sure to buy disease-free seeds. Some vegetables do better if transplants instead of seeds are planted in the garden. Transplants are young plants grown from seeds started indoors and bought from a store.

How to Plant

Plant in straight rows. This makes it easier to tell the weeds from the vegetables. Also cultivation and harvesting are more convenient. Drive two stakes into the ground at each end of the garden and draw a string taut between them. Small seeds should be planted in shallow furrows (trenches). These can be made by drawing a hoe handle along the line indicated by the string.

20 For larger seeds and deeper furrows use the corner of he hoe blade. Seeds may be planted by the hilling or the drilling method. For the hilling method several seeds are placed in one spot at definite intervals in a row. Sweet corn, squash, melons and cucumbers can be planted in this way. Most seeds are sown by the drilling method.

Seeds are spaced evenly down the row. After planting, cover by firming the soil around the seeds. Plants should be thinned before they are over 2 inches tall. Remove the weakest plans.

Begin with the Best Plants When buying transplants, avoid tall, spindly plants. Short, stocky transplants are preferable. About a week before planting begin setting transplants outside each day for a few hours. This will get plants adjusted to the outdoors. Vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, eggplant, sweet potato and tomato are grown best from transplants.

Planting Transplants Plants should be set in the garden on a cloudy day or in the evening. Water the plants about an hour before transplanting. Carefully remove plants from the pot without disturbing the roots. Keep a ball of soil around the roots. Some transplants are grown in peat pots. These pots can be planted directly into the garden. Dig a hole large enough for the transplant to set slightly deeper than it grew in the container. Use a starter solution. Plant roots should be covered with soil.

Firm the soil around the plant. Plants may be protected from heat, wind or cold when necessary. Cups, jars, cartons or baskets can be placed over plants for protection. Be sure to remove the protector when the weather improves.

Harvesting Vegetables Most crops can be harvested several times if only the part that is ready is harvested.

The quality of vegetables does not improve after harvest so it is important to gather crops at proper maturity. At this point vegetables are at their peak for flavor and nutrition. This is not always when a vegetable is at its largest stage. This ripe time varies with certain vegetables. Tomatoes may be left o the vine until fully ripened or taken off when partially ripened and placed on a windowsill to mature. Other crops such as winter squash and watermelon are not ready until after they are fully developed.

Handle Plants with Care Avoid bruising or damaging vegetables as this causes decay. Stepping on vines or breaking stems creates openings through which diseases can enter the plant. If ripe vegetables are not easily removed from the plant, cut them off with a knife. Tramping through wet foliage helps to spread plant diseases. Harvest vegetables when they are dry. Check the garden frequently for ripe produce during harvest time. Vegetables continue to grow and before long they are overgrown.

Harvest Time  Beans, snap - Harvest when pods are almost full size but before the seeds inside begin to bulge. Tips should be pliable. Beans should be crisp and snap easily. Harvest often.

21 

Beans, Lima – Pick when pods and seeds reach full size and before turn yellow.

End of pod should feel spongy. Pods and seeds should be fresh, juicy. Open a few pods to check. Use only seeds. Pods are tough and fibrous.



Beets – Beets can be eaten as greens when the leaves are 4 to 6 inches long.

When grown for tops and beets, harvest when beets are 1 to 1-1/2 inches in diameter. To use only the beets, wait until they are 1-1/2 to 3 inches in diameter.



Broccoli – Gather when buds are compact and before buds turn yellow or open into flowers. Cut off 6 to 7 inches below flower heads. Small, tender leaves also are nutritious.



Brussels sprouts – Pick when sprouts (buds) at the base of plant are firm.

Don’t strip leaves since they are needed for growth. Pinch out growing point at top of plant to get larger sprouts.



Cabbage – Harvest when heads are firm and before mature heads split.

Splitting is caused by excessive water uptake. To avoid this, give the head a quarter turn to break several roots.



Carrots – Carrots are ready when 1 inch in diameter. They may be left in the ground for later harvest during cool, dry periods.



Cauliflower – It’s ready when head is firm. It’s over mature when soft or when leaves turn yellow. When heads are a diameter of 2 to 3 inches, take outer leaves and told them up and over the head. Tie them with a string. This keeps head from turning yellow. In 1 to 3 weeks diameter of head should be 6 to 7 inches and ready to harvest.



Corn – Kernels plump, milky when mature. Silks are brown, dry. Corn is at prime eating quality for only 72 hours before becoming over mature. Harvest early in the morning or during cool weather.



Cucumbers – Pick when 6 to 9 inches in diameter. Over mature fruits are dull in color or yellow and less crisp. For sweet pickles, fruits should be 1-1/2 to 2-1/2 inches long, and for dill pickles, 3 to 4 inches long. Do not raise vines when picking as this may damage the vines and reduce yields.



Eggplant – Harvest when 4 to 6 inches in diameter. Skin should be shiny, dark purple. Fruits are over mature when dull in color, soft and seedy.

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Greens – Collards, kale, chard, mustard – Cut outer leaves when 6 to 8 inches long.

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Lettuce, Head – Pick when heads are moderately firm and about 6 inches in diameter.

22 

Okra – Pods are ready when 3 to 4 inches long, about 4 to 6 days after the flower wilts. Pods stop producing if not picked, so gather them every 1 to 2 days.



Onions – Harvest when tops fall over and begin to die. Dig bulbs and dry for several days. Cut off tops and roots and store in a cool, dry place. Harvest green onions when they are 6 to 8 inches tall.

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Peppers – Peppers are shiny green in their prime and about the size of a baseball. They still are good after turning red or yellow. Hot peppers are red or yellow when ripe.

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Sweet Potatoes – Sweet potatoes should be harvested before the first frost. Lift to avoid bruises and broken roots. Cure in a warm well- ventilated place for 2 to 3 weeks.

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Radishes – Pull them up when they are about 1 inch in diameter. Radishes become hot and tough when left in the garden too long.

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Rutabagas – Rutabagas are mature when 4 to 6 inches in diameter. They become woody and dry if soil is too dry.

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Spinach – Leaves are ready when 4 to 6 inches long. Pull out larger, whole plans or harvest older leaves to allow new growth.

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Summer squash – Zucchini, cocozelle, crookneck, straightneck, scallop – Pick when seeds and fruits are small. Squash should be 6 to 8 inches long with skin you can puncture with a fingernail. Continue to harvest.



Winter Squash, Pumpkins – Butternut, buttercup, acorn, hubbard – Harvest when fruits are full size. Rind should be firm and glossy and bottom of fruit is cream to orange color. Leave squash on stems for better storing and pick before fall frost.



Tomatoes – For canning or juice pick fruits that are fully colored. If cracking at the top is a problem in hot weather, pick them when they are turning pink. These tomatoes will ripen in the shade indoors. Before the frost, pick green tomatoes and store in a dark place when they can ripen.



Turnips – Harvest when roots are 2 to 3 inches in diameter but before the frost.

When grown for greens, pick leaves when 4 to 6 inches in length.

Vegetable Chart Components

Different types of vegetables will be explored in this lesson using a chart format. The chart addresses some of the most important factors that must be considered when deciding what vegetables to grow. Descriptions of each heading are given following the sample chart. Recommendations will vary depending on such factors as the local climate and region and the specific varieties of vegetables grown.

23

Sample Vegetable Chart Cool Season Root Crop Days to Germination Days to Maturity Soil Spacing Harvest Post-harvest Production Concerns Pests and Diseases Other Considerations



Days to Germination: The days to germination are the estimated number of days before a plant will begin to grow and sprout.

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Days to Maturity: The days to maturity are the estimated number of days from planting until a usable or salable product can be harvested.

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Soil: This section of the chart explains what soil conditions are desirable for the plant to grow, such as the recommended soil pH, texture, and drainage.



Spacing: Spacing requirements provide a guideline for how much space to leave between plants and rows to allow adequate room for growth, cultivation, and harvesting.



Harvest: The harvest section provides general guidelines to help determine when the crop is ready to be harvested and how to harvest the crop.

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Post-harvest: Proper storage and handling procedures are listed in the postharvest portion of the chart.

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Production Concerns: Crop-specific information to facilitate proper growth and production is supplied in the production concerns section.

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Pests and Diseases: This section lists common pests and diseases that affect the specific crop.

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Other Considerations: This heading provides a place to include crop-specific concerns that are not associated with other areas of the chart.

24 Unit IV Insect Control PESTS: WEED AND INSECT CONTROL METHODS Objective: To provide readers with information on ways to control weeds and insect pests.

After reviewing this unit, the learner will be able to:  tell why some plants and some insects are pests.  describe pest control methods.  explain who should use chemicals to control pests.  describe circumstances which make pesticides necessary.  explain ways to determine what type of pesticide to use.  discuss potential health and environmental hazards resulting from pesticide use.  list pesticide labeling’s “signal works” and tell what they represent.

Pests are unwanted organisms (plants or animals). Some pests are harmful or detrimental to high quality production of food and fiber. They can cause damage to gardens and farm crops. In some instances, pests can completely destroy a crop.

Some pests transmit diseases that interfere with the normal growth and development of plants. The primary food and fiver pests are usually insects or weeds. It is possible to control these pests through natural methods (sustainable agriculture) or through the use of chemicals called pesticides.

People of often think that all unwanted organisms are bad and must be destroyed. This is not true. The most destructive pests have some type of purpose, even if it so simple a purpose as serving as the primary source of food for another insect. Some pests will naturally disappear, or leave on their own, and do not need to be treated by any specific method. And there are insects which may inflict damage during one stage of development, but then become helpful as metamorphosis continues, so it is important to know the growth stages of the insect in question.

Pest Control. When is a plant considered a pest?

Plants that are pests are called “weeds.” Weeds are unwanted plants growing out of place. Weeds are pests for several reasons. They take up space in a field or garden.

They draw nutrients needed by other plants out of the ground. They absorb water that other plants want. Weeds also shade shorter plants from the sun. Finally, weeds sometimes grow in such a way that they literally choke or strangle other plants.

Pest Control. When is an insect considered a pest?

Insects become pests when they feed on the growing plant. They can destroy the developing plant by feeding on the plant during various stages of insect metamorphosis.

Because they have the ability to reproduce quickly, they are a serious threat to the garden or farm.

Although pest insects can do a lot of damage to a growing plant, it is important to know that most insects are not pests.

25 Many kinds of insects can be found in your garden. Some insects are destructive.

Others are beneficial, such as lady beetles, because they feed on destructive insects.

Aphis lions feed on aphids. Parasitic wasps feed on caterpillars and other insects.

Insects that attack vegetable plants are divided into three groups – sucking, chewing and boring.

Sucking insects feed on plant juices, sucking them out and causing the leaves to turn a yellow or bronze color. Leaves and plant shoots also may wilt and curl.

Chewing insects eat holes in leaves, flowers or fruits.

Boring insects get inside plants. These pests before into stems or mine shallow tunnels into leaves, fruits and roots.

When trying to tell if a plant is suffering from insect or disease problems, there are two symptoms to remember. Insects may eat plant material, leaving holes on the leaves and also leaving waster material near the feeding area. This waste material may be in the form of a sugary syrup, granules, sawdust-like material or moist, dark excreta.

These symptoms do not occur with plant diseases. Insect-infested plants also may be stunted.

Insects – Good Bugs and Bad Bugs As insects complete their life cycles, they may go through various structural changes or metamorphosis. Some insects change only in size as they age (e.g. aphids). These insects undergo no metamorphosis. Other insects undergo only slight changes (or a simple metamorphosis) as they age from nymph to adult (e.g. grasshoppers). A final group of insects undergoes a complete metamorphosis as they pass from egg to larva to pupa to adult. Insects at some stages of their life cycles may be more destructive than they are at others. Similarly, insects may be easier to control at some developmental stages than they are at other stages. To develop a successful control strategy, it’s important to know the stages of a pest’s life cycle.

Insects. What does an insect look like?

Insects are related to crabs and lobsters because they have a skeleton-like structure on the outside of their bodies. They have three main body parts (head, thorax and abdomen). Six jointed legs are attached to the thorax. Antennae and two large compound eyes are found on the head. Most adult insects also have two large pairs of wings. Four different types of mouth parts (piercing-sucking, chewing, sponging, and syphoning) are found among insects.

The insect’s mouth type determines what it eats. Piercing-sucking mouth parts allow an insect to punch through the skin on a plant or animal and suck out its “juices” (e.g. aphids, mosquitoes).

Chewing mouth parts allow an insect to take a bite out of its food (e.g. caterpillars, beetles). Sponging mouth parts allow an insect to lap up food on a surface (e.g. flies).

Syphoning mouth parts allow an insect to remove nectar from flowers (butterflies, moths).

26 Insects. How are insects important in the food chain?

Energy comes to earth in the form of sunlight. Plants intercept this light energy and convert it into chemical energy through photosynthesis. Many insects eat plants and store this chemical energy in their bodies. Larger insects eat smaller insects. Large and small insects alike serve as food for birds, fish and other animals. In turn, these animals are eaten by larger animals. Many animals eat insects as their primary diet. If insects were eliminated from the food chain, this could also eliminate animals who feed on insects, and the predators of those animals.

Insects. How many insects are considered pests?

Less than one percent of the nearly one million insect species in the world are considered pests to humans, our domestic animals, or plants used by us for food, fiber, or ornamental purposes. Of the 100,000 insect species found in the United States, only about 600 are considered economic nuisances. Most of the remaining insects are of no economic importance. Still other insects are beneficial to us.

Insects. How are insects beneficial?

Although insects are known as our worst enemy, some have economic value, and for that and other reasons, it would be difficult to exist without them. Some insects (e.g. ladybird beetles, lacewings) eat pest insects. These insects are referred to as predators. Other insects (e.g. Braconid wasps) lay their eggs in the bodies of other insects. The larvae form these eggs feed on the internal organs of the host, killing the host. These insects are parasites. Some insects (e.g. honey-bees, wasps and moths) pollinate crop plants (e.g. melons, apples, peaches, clover). Honey and wax from the honeybees, and silk from silkworms are examples of important commercial products obtained from insects.

Insects. Why is identifying the pest an important step in pest control?

Properly identifying the pest is necessary to determine what caused the damage. The presence of an insect on a pest-damaged plant does not necessarily mean that the insect caused the damage. The insect’s presence may be unrelated to the damage, or the insect may be feeding on the pest which caused the injury. Proper identification will prevent killing the wrong insect, and ensure that an appropriate control method will be used.

Insects. What are some examples of pest control methods?  Some varieties of plants are resistant to insect pests. These varieties are grown to prevent damage.  Some insects can be trapped to lower the pest population.  In some situations, a habitat which encourages beneficial insects can be created.

   

In other situations, beneficial insects may be released into an area to supplement the native population.

Physical barriers, such as screens or nets, may be used to exclude the pest from an area.

Insecticides may be used to control insect pests.

In some situations, the best solution may be to do nothing. It may be determined that the damage is not severe enough to warrant any further control methods.

27

Destructive Insects Insect

Description Crops

Aphids or plant lice Tiny (less than 1/8 inch long), softbodied, usually wingless insects. Color ranges from pale green to black. Slowmoving. Often not noticed until there are many upon a plant.

Attacked Symptoms

Bean, broccoli, cabbage, cucumber, Irish potato, muskmelon, squash, sweet corn, tomato, watermelon.

or

Damage

Curled leaves; "honeydew"(clear, sticky substance on leaves and fruit given off by aphids, turns black from mold growth); many tiny, softbodied insects.

Blister beetles Bean, Irish potato, tomato 1/2-5/8 inch long. Soft-winged black, gray, or striped beetles. Fast-moving.

Usually appear in groups.

Blister beetles damage foliage by chewing and by secreting a toxin that causes wilting and leaf-burn. If unchecked, beetles can strip foliage from plants in a short time.

Cucumber beetles 1/4 inch long. Black and yellow spotted or striped beetles. Feed on foliage, flowers, stems, or fruit. Fly from one plant to another.

Cucumber, muskmelon, squash (summer and winter), pumpkin, watermelon.

Holes in foliage; chewed flowers; scarred stems and fruit surfaces.

Beetles may carry bacterial wilt disease that causes plants to wilt and die.

Cutworms Up to 1-1/2 inches long. Black, gray, or mottled caterpillars. Usually a single cutworm found curled up beneath soil surface at base of damaged plant.

Broccoli, Brussels sprout, cabbage, cauliflower, eggplant, kohlrabi, pepper, sweet corn, tomato.

Cut-off or wilted plants. Cutworms chew through plant stems at or just beneath soil surface. They may also feed on ripening tomato fruits, leaving small, round holes.

Flea beetles Shiny, usually black beetles, often not observed because of their small size (1/16 inch) and ability to jump quickly from plants when disturbed.

Cabbage, Chinese cabbage, eggplant, radish, spinach, sweet corn, turnip.

Flea beetles scratch holes or leave white streaks in green foliage in late spring. Intense feeding results in wilting and dying of leaves and decreased yield.

Grasshoppers Most vegetables.

Vary widely in size, up to 1-1/2 inches long. Color ranges from green to brown.

Hop or fly. Young present in early summer, develop into large-winged adults by late summer.

Holes chewed in foliage.

Leafhoppers Bean, carrot, cucumber, Up to 3/8 inch long. Green color. Wedge- Irish potato muskmelon. shaped. May migrate from one area of garden to another. Hop away in large numbers when foliage is disturbed.

Curled or crinkled foliage; "hopper burn"(caused by leafhoppers' feeding, indicated by brown edges on leaves). Leafhoppers may have migrated from damaged plants.

Maggots, root Cabbage, onion, radish, Wilting or stunting of plants.

Tiny (up to 1/8 inch long), white, legless rutabaga, turnip.

Numerous brown or gray tunnels worms. Found in tunnels in underground throughout underground parts of parts of vegetables. Usually confined to vegetables. northern one-third of Illinois.

Slugs Most vegetables. (snails without shells) Range in size up to 2 inches long. Shiny, slimy, soft, legless animal. Seldom seen in daylight.

28

Paths of slugs marked by shiny mucous trails. Some feeding on foliage and scarring of fruit.

Pest Control. Is one of these methods of control better or more effective than another?

The use of chemicals is the surest way of eliminating most pests. Natural and biological control depend on other factors, such as the availability of beneficial insects or the right amount of rainfall, to be completely effective. However, because there are so many types of insect and weed pests, there is no single best method of controlling them.

Pest Management Recommendation for preventing or controlling insect damage. Keep the garden free of weeds and mow the surrounding area. Plow under or remove plants that are finished producing. Do not leave them planted in the garden.

Plant varieties that grow well in your area and follow proper fertilizing and watering recommendations. Some insects such as aphids a spider mites may be washed off the plants with a garden hose. The tomato hornworms or insect egg masses may be hand-picked from the plant to prevent further damage.

Crop rotation will help hold down the population of chewing insects. When buying an insecticide, read the label to see if it is recommended for the insect and plant you are treating. Follow the directions. When using chemical control for sucking insects, spray the underneath of the leaves as well as upper surfaces. Insecticides are most effective if used before large numbers of insects take over the plants.

Chemical Pest Management The use of chemicals to protect and treat plants and to repel or destroy pests is called chemical pest management. The most common type of chemical pest management is the use of pesticides. There are many different types of pesticides.

Type of Pesticide

Pests Treated

Bactericide

Bacteria

Fungicide

Fungi

Herbicide

Plants

Insecticide

Insects

Miticide

Mites, ticks

Molluscide

Snails, slugs

Nematicide

Nematodes

29 Pesticides can be a very useful tool in managing pest populations, but they do pose potential risks. Pesticides are specifically designed to adversely affect or kill the pests they target.

If mishandled, they can present health risks to humans and cause damage to the environment. Pesticide use is monitored and regulated by various local, state, and federal agencies, including the U.S. Environmental Protection Agency (EPA). The EPA evaluates new pesticides and reviews old ones to determine that they can be used safely and without causing an unreasonable threat to the environment. Growers should follow all directions and regulations regarding the proper use, handling, and storage of any pesticides they use.

Pests can develop resistance to chemicals over time, so using pesticides alone should not be the only method for treating pests. Pesticides should be only when necessary and at the lowest rate of application that will effectively control the pests. This reduces expense, helps prevent pests from becoming resistant, and lowers health and environmental risks.

Biological control involves human intervention to naturally control pests.

Biological control is the intentional use of living organisms, such as parasites or predators, to eliminate pests or suppress them to acceptable levels. It relies on knowing where certain insects fit in the food chain. Biological control is environmentally safe because no chemicals are used. An example of biological control is releasing large quantities of “good” bugs in an area populated with “bad” bugs. The good bugs are predators of the bad bugs, and they reduce the population of bad bugs by eating them. Another example of a biological control method is growing certain plants that actually repel the insect pest. Marigolds, for instance, can be planted around the perimeter of the garden to repel nematodes. Hand removal of pests is yet another biological control method used by some farmers.

Cultural Pest Management Cultural pest management is controlling pests through the use of proper planting and growing techniques. Good cultural pest management begins by choosing varieties that are suited to the area and planting them so that growing conditions are optimized and stress on crops is reduced. Providing adequate water and nutrients helps ensure strong plants, which are more resistant to pests and diseases and more able to outgrow weeds. Crop rotation, proper disposal of plant residue, and planting and harvesting to avoid coinciding with pests are also examples of cultural management strategies.

Cultural pest management works by optimizing conditions for crops while minimizing opportunities for pests. Cultural management strategies have the advantage that many of them can be implemented before pests appear.

30 Physical and Mechanical Pest Management Physical and mechanical pest management strategies use physical barriers and labor to prevent or limit pest damage. Examples of physical pest management would include using fencing, traps, row covers, and trenches to

keep pests off crops. Mowing, plowing, and hand-picking insects off plants are examples of manual operations that can be used to control pests.

Holding produce in cold storage to kill pests or slow or stop their development is also a type of physical pest management.

Some physical and mechanical strategies, such as removing insects by hand, can require too much time and labor to be practical for larger operations. The size of the operation and the availability of a labor force should be considered before using physical and mechanical management strategies.

Integrated Pest Management Integrated pest management (IPM) combines biological, chemical, cultural, and physical and mechanical strategies into a comprehensive system of pest control. Integrated pest management programs have the following goals:      

Limit pests to acceptable levels Promote healthy crops and good land management Reduce reliance on pesticides Promote long-term management strategies Improve health and safety for farm workers and consumers Limit damage to the environment

It is important to realize that IPM does not attempt to eliminate all pests. Some pests are acceptable, because limited pest populations help maintain the predator and parasite populations that are utilized for biological control. The key to IPM is knowing when the pest population passes the acceptable level—the point at which the cost of damage is greater than the cost of controlling the pests. This point is called the action threshold or economic threshold, and it is when the producer must take steps beyond any preventive measures already in place.

Six Steps of IPM

Implement preventive strategies.

Scout plants for symptoms or presence of pests.

Identify pests and scope of damage.

Determine when action must be taken.

Implement management strategies.

Evaluate results.

31 There are a number of factors that should be considered when determining the action threshold, such as the level of damage and infestation, market price, stage of crop growth, and cost of pesticides.

A successful IPM strategy requires a thorough understanding of the crops, the potential pests and their enemies, and the surrounding environment. The producer must know how these elements interact, and monitoring the site for pest activity is critical.

There are many advantages to an integrated pest management system.

Utilizing a variety of controls reduces the likelihood that pests will adapt to one particular strategy. A number of IPM strategies are simply good planting and management strategies, and therefore cost little or nothing extra to implement.

Integrated pest management also reduces dependence on pesticides and helps promote healthy produce and a healthy environment. A healthy environment can support a balance between agricultural production, native plants and animals, and human inhabitants. An environment in which the natural resources have been depleted or misused cannot. Integrated pest management offers affordable, workable solutions that can benefit consumers and producers.

Pest Control. What are the various application forms of pesticides?

Pesticides come in a variety of forms. They can be found in aerosol spray cans or bottles that can be easily used by an individual.

Some pesticides are available in a dust or powder form. Others can be found in a concentrated form that must be diluted properly before it is used. Still others are founds as baits and granules. They can usually be purchased in several different size packages, depending on specific needs.

Pest Control. How do you determine which pesticide to use?

Before you decide to control or eliminate a weed or an insect, you must determine if it is really a pest, or if it is something that is actually beneficial to the plants. Once you determine that the insect or weed is detrimental to the plants, and then it may be necessary to proceed with control methods, but remember that insects have different feeding habits during their various life cycles stages. Once you know the type of insect you want to control, you should rely on package labels to help you know if that particular product is appropriate for you situation. Because all pest – both plants and insects – are different, it is usually not possible to control them with just one pesticide. For example, one insecticide will not eliminate all insects, because of their varying feeding habits and their life cycle stages.

32 Pest Control. Are there any potential health or environmental hazards to chemical pest control methods?

There can be. Pesticides must be poisonous in order to kill pests. This means that they might be harmful to humans as well as the pest. Some are made of ingredients similar to nerve gas. If these pesticides are not used properly, they can cause harm to humans and damage the environment. Some pesticides are more harmful than others. If they are used improperly, some pesticides have the power to completely eradicate entire populations of some insects and weeds. This type of eradication would most likely cause problems for other plants and animals in the food chain.

The best pesticides for the environment are those that do what they are supposed to do and quickly dissolve in the ground. If an insecticide does not dissolve, the residue can be carried onto the harvested product or eaten by animals, and eventually consumed by humans.

Careful, informed and appropriate use of pesticides can be beneficial to home gardeners and farmers alike.

Pest Control. How can someone tell how toxic (poisonous) a pesticide really is?

All pesticides must have a label that describes what should and should not be done with that particular product. Part of the label includes a signal word and symbol, if appropriate, that tells the toxicity level of the product. There are three signal words, one of which will be on the label: caution indicates a low level of toxicity, warning indicates a moderate level of toxicity, and dangerpoison with a skull and crossbones indicates a high level of toxicity. The label may also recommend specific protective measures to take when using the pesticide.

Pest Control. Can anybody use all pesticides?

No. Some pesticides are restricted. This means that to purchase and use them, a pesticide license is required.

The person who has the license must read, understand and adhere to the specific laws and regulations regarding the pesticides being used.

33

DINNER’S READY

What To Expect Participants will recognize harmful and beneficial garden insects and explore choices to control them.

Materials Needed  Insect identification books  Paper  Scissors  Glue LIFE SKILLS  Critical thinking  Planning and organizing  Keeping records  Accepting differences  Sharing PROCESS SKILLS  Acquiring, processing and interpreting data 

Designing investigations



Analyzing investigations

Getting Ready  Review Don’t Be a Pest background information and discuss with the group. 

Have youth take the Pests: Weed and Insect Control Methods pre-test found in What’s the Score?



Review Your ID, Please! if the students did not complete this activity.

Listen Up! It’s a fact of life, if you plan to grow a garden, you will observe insects feeding on your plants. You have two choices: one is to tolerate the damage they cause; the other is to prevent them from causing further harm to your garden. It is important to understand that many insects are predators and parasites of harmful insects. Often, these beneficial insects will control the harmful pests well enough that other methods of control are not necessary.

34

There are three primary methods of insect control. These methods are natural control, biological control and chemical control. An insecticide is any product which, when applied, kills insects. Nearly all insecticides available for garden use are safe; however, all insecticides are potential poisons, and should be handled and used with care. Let’s explore some choices we have for controlling insects.

Activity  If the youth completed the Your ID, Please! activity, have them refer back to the Insect Identification Guides they made. 

If you skipped Your ID, Please!, ask each youth to select 10 insects from the following list and find pictures or drawings of them: Aphids Asparagus beetle Cabbage looper Corn ear worm Cutworms European corn borer Grasshoppers



Honeybees Japanese beetle Lacebugs Lady beetles Lacewing flies Mole crickets Parasitic wasps Potato leafhopper Spider mites

Squash bug Striped flea beetle Tomato fruitworm White grubs Wireworms

Using the insect you selected, (wither from the Your ID, Please! Or the list above) research and write a brief description about each of the following: o Specify whether the insects are harmful or beneficial to plants o Describe what stage of development for each insect causes the greatest damage to plants o List any plants the insects feed on o Label whether each insect is a predator, a parasite, or neither to other insects o Identify control methods recommended for each insect



Instruct the participant to add this information to their Insect Identification Guides. If they do not have a Guide, have them to create one using this information.

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Share  What did you learn about insect control in this activity?  What information about the insects was the most difficult to find?  How difficult was it to find illustrations of insects?

Process  

When is conducting background research important?

What parts of conducting background research seemed most difficult?

Generalize   

How does conducting research help you solve problems?

What other kinds of guidebooks or records does your family keep?

How does having a photo or a drawing help you to positively identify? Other similar things?

Apply    

In what other areas of your life will you use identification guides to solve a problem?

How will you use what you learned in this activity?

If you want to find out more about the name of an “unknown,” how would you do it?

How will you apply what you have learned in this activity in your Down-ToEarth garden?

Want To Do More?

Have the participant:  Visit the local law enforcement center to find out how they positively identify people.  Invite a beekeeper to the session to discuss the importance of honeybees.  Investigate and write about a career in ecology.

Test Your Knowledge 

Have participants take the Pests: Weeds and Insect Control Methods posttest found in What’s the Score? if not taken in the previous activity.

36

Unit V Disease Control Objective: To provide readers with background information on plant diseases.

After reviewing this unit the reader will be able to:  explain types of diseases  controlling diseases Plant health can be threatened by diseases, insects, weed competition, animals, and changes in the environment or poor care.

Diseases and insects often attack plants despite good growing conditions and care. They cause similar damage but in different ways. Both may cause leaves or fruits to be distorted, spotted and decayed. Both may result in the loss of leaves or leaf discoloration. By closely observing damaged plants, it is usually possible to distinguish disease from insect damage.

Diseases that attack vegetable plants are caused mostly by fungi, bacteria, viruses and nematodes. These organisms are spread by the wind, rain-splash, insects, infected seed or transplants, and by the movement of infested soil.

Many bacterial and fungal diseases cause discoloration of the leaves. An area in the leaf may turn yellow, gray, brown or black. Infection may remain as a small, discolored spot or expand into a large, irregularly shaped dead area.

These infections often have a yellow to light green, brown or black margin or "halo" around the original diseased area.

Types of Disease Damping-off Damping-off is a disease caused by soil fungi that attack germinating seed and seedlings. A seedling collapses and dies when it is attacked at soil level.

Damping-off can be avoided partly by planting seeds in warm, well-drained soil in a sunny spot and by proper culture (correct planting depth, spacing, watering and fertilization).

Most commercially purchased vegetable seed has already been treated against seed decay and damping-off. Drenching the seedlings as they emerge from the soil with a fungicide is often beneficial.

Fungus Diseases of Older Plants There are many different types of leaf and stem spots and blights. Fungicides will prevent common leaf and stem blight diseases of carrots, cucumbers, Irish potatoes, melons, pumpkins, squash, peppers, tomatoes, and eggplants.

37 To control these diseases, select a recommended fungicide and cover all plant surfaces. Some diseases, such as Fusarium and Verticillium wilts, are best controlled by planting resistant varieties.

Virus Diseases Viruses may cause plants to be stunted with the leaves mottled and deformed.

Viruses are spread from weeds and diseases plants to healthy plants by the feeding of insects (mainly aphids, leaf hoppers, thrips, and a few beetles). A few viruses can be spread by cultivation, pruning and harvesting. Virus-infected plants should be removed from the garden when first found.

Nematode Diseases Nematodes are small, transparent, worm-like animals that live in the soil. They fed on plant roots, often causing the plant to lack vigor and be stunted and yellow. Root-knot nematodes burrow into the roots of plants causing small, knot-like galls in the roots.

Do not confuse these galls with the larger, beneficial bacterial nodules which are attached loosely to the roots of peas and beans.

Root galling causes plants to grow slowly or to wilt on hot, dry days. If root-knot nematodes are found, change the location of the garden or fumigate the area with a soil fumigant. Carefully follow the directions on the container.

Controlling Diseases Taking proper care of plants will help to keep them strong and more resistant to disease. Follow good fertilizing and watering practices. Control weeds and insects.

Mulches help to control fruit rots and blossom-end rot of tomato and pepper (dark, sunken area on bottom of fruits).

Run the water between the rows as sprinkling the leaves encourages diseases problems. If you must get the plants wet, water in the morning before 10 a.m.

Do not work in the garden when plants are wet. Cultivating, pruning or harvesting under these conditions spreads bacteria and fungi from infected to healthy plants.

When disease is seen on leaves, stems and fruits, carefully remove the diseased part, place in a paper sack and put it in the trash can. Check the garden every few days.

Fungicides can be used as dusts or sprays. They are most effective when used before a leaf spot or blight appears. Follow the directions on the container.

38 Grow varieties that are disease resistant and use seeds or other planting materials (bulbs, tubers, sets) that are disease-free and have been treated with a fungicide. Do not save your own seed for planting.

Rotate vegetables by planting them in different locations in the garden each year. Avoid planting any of the vegetables in each of the following families in the same location more than once every three years.

For example, cabbage and turnips should not be grown in the same location for two succeeding years. This is true for the entire cabbage family: broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, mustard greens, radish, kohlrabi, rutabaga and turnip.

39

Unit VI Water Objective: To provide readers with background information on water resources and how these resources can be affected by human activities.

After reviewing this unit, the learner will be able to:  explain why water is an essential element for all living things  identify basic components of the water cycle  discuss how natural influences affect water quality  explain how human activities can diminish water quality  discuss ways water contamination can be prevented or minimized Our water resources, like all natural resources, need our protection if we are to enjoy continued use of them. We depend on water for a variety of uses in addition to personal consumption. Our farms and industries use enormous amounts of it.

But almost 97 percent of the water found on earth is salt water, located in oceans and seas. Such water is not usable for drinking or farming without treatment. Good drinking water is virtually colorless and odorless. It is free of harmful contaminants, contains few microorganisms, solids (dissolved and suspended), metals and salts. Most importantly, good drinking water tastes good.

Public concern about ground water contamination continues to grow. Today, we have the technology to detect contaminants (chemicals, microorganisms) in very small amounts, which previously went undetected. Ground water contamination comes from natural influences and human activities. Because water is the universal solvent, it gathers a little of everything it contacts as it flows – dissolved organic matter, soil nutrients, and naturally occurring suspended particles. Human activities which can lead to ground water contamination include everything from waste disposal to well drilling; everything from basic agriculture to heavy industry. All too often, the health and environmental risks of contaminants which human activities put into ground water are uncertain.

What is water all about?

Biologically, water is the essence of life. Physically, water can exist in three forms: as a liquid, as a solid (ice), and as a gaseous vapor (steam).

Chemically, water consists of two elements: two atoms of hydrogen (H) and one of oxygen (O), which combine to form the compound H2O. Pure water is neither an acid nor a base (alkaline). Hydrology is the study of water, and hydrologists are scientists who study water.

40 Is there a difference between pure, fresh, salt, and treated water?

Perhaps at the beginning of time, all water was pure – totally uncontaminated.

Today, the chances of finding pure water on Earth are virtually nonexistent.

Eventually, no matter where the water comes from, gravity pulls it to the ocean where it becomes salty. The hydrologic cycle cleans water and changes salt water into fresh water through a natural purification system.

Salt water – has a salinity (salt) content greater than fresh water. When water condenses, the molecules surround dust particles. This water often gathers together in droplets so large that gravity pulls them to Earth as precipitation.

Each time water evaporates or transpires, it leaves behind salts, minerals, and other substances dissolved in it. Water covers most of the Earth (75 percent).

Despite this abundance, all but 3 percent is salty ocean water is unusable for drinking or farming. Natural seawater has a salinity of about 35 ppt (parts per thousand).

Fresh (raw) water – is untreated ground water or surface water (rivers, lakes, streams, and ponds). Raw water may or may not contain contaminants. The salinity level of fresh water is less than 1 percent (usually 50-70 milligrams per liter).

Treated (finished) water – is raw or salt water chemically treated to remove harmful contaminants so it is safe for drinking.

Pure water – would not be very good for drinking because it is colorless and tasteless. Many naturally dissolved minerals and salts that give water its flavor, and are necessary for life and health, would not be found in pure water.

Is it possible to get some of our water needs from eating plants?

Yes! Because many plants are full of water, it is possible to get some of our water needs from them. For example, a tomato is 90 percent water, and 80 percent of a pineapple or an ear of corn is water.

Why is water so important for plants?

With the help of sunlight, most plants make their own food molecules (sugar and starch) from water and air. Plant roots absorb water from the soil.

This water carries minerals from the soil up the stem to the leaves. Part of the water entering the plant evaporates (turns into a gas – water vapor). Water vapor returns to the atmosphere through tiny openings (stomata) on the underside of leaves. This process of water uptake that also cools the plant is known as transpiration.

41 Some absorbed water is split and used to form other molecules. The split water molecules combine with carbon (C) from carbon dioxide (CO2) to create “building blocks” to build cell tissue. Oxygen (O2) from the carbon dioxide (which enters through plant leaves) is also released back into the atmosphere through their leaves. The water that stays in the plant cells helps to keep them firm. Cell water also serves as a storage place for minerals and other molecules. The complete food making process is called photosynthesis.

When does a plant use lots of water like people?

During photosynthesis and transpiration, plants use large amounts of water.

One bushel of corn requires about 4,000 gallons of water to grow. A bushel of wheat requires about 11, 000 gallons of water, and about 135,000 gallons of water are needed to grow a ton of alfalfa. On the other hand, about 1, 400 gallons of water are required to produce to just one meal which consists of a quarter pound of hamburger, French fries and a soft drink.

How much water does the average American use per day?

While usage varies from community to community and person to person, on average we use 183 gallons of water daily for cooking, washing, flushing, and other personal and household purposes. About 74 percent of the water Americans use is used in bathrooms. We use about two gallons of water to brush our teeth per person per day. While plants transpire much of the water they use back into the atmosphere as clean water vapor, the water used by people needs to be cleansed before it is ready to be used again.

With the Earth’s population increasing and available sites for reservoirs decreasing, demands on this valuable resource will probably continue to rise in the coming century.

Can water be a problem for plants?

Ask anyone who grows plants – they will probably tell you that water can be a problem, and water can be a solution. Water, moisture, precipitation – it seems like there is never enough, or, occasionally, too much. One inch of rainfall produces 27,000 gallons of water per acre. Too much or little water will kill plants.

How can we tell if plants in our garden are getting enough water?

Ideally, the soil should be moist enough to dissolve nutrients so root hairs can absorb them. But the soil should never be so wet that water fills the air spaces scattered through it.

How do we decide how often to water?

The frequency of watering depends on two factors: weather and the water retention capacity of the soil.

42 Although there is no definite rule for watering gardens, most gardens should be heavily watered once a week except during periods of heavy rains. Light, daily watering will establish shallow roots, which can dry out quickly, and become inadequate for getting water to the plant even when there is more moisture in the soil.

Because moisture drains through light soils (sandy, silt) faster than heavy (clay) soils, water plants in light soils more often than those in heavy soils. Roughly, one-and-a half inches of water must slowly fall on the soil weekly in order to establish deep roots six inches below the ground.

Does it matter what time of day we do our watering?

The best time to water garden plants is early in the day. This allows them time to dry completely before sunset. Dampness and darkness combined make plants susceptible to disease.

How much water does agriculture consume?

Irrigation uses almost 70 percent of all water pumped from the ground daily in the United States. Agriculture consumes 65 to 70 percent of our fresh water resources, not only in the U.S., but worldwide. About 30 percent of the ground water used for irrigation in the United States comes from the High Plains Aquifer, which runs beneath parts of Colorado, New Mexico, Kansas, Nebraska, Oklahoma, South Dakota, Texas, and Wyoming.

Why is protecting our supply of fresh water so important?

While pure water is unnatural, clean water is cherished. Fresh water is a limited natural resource whose distribution is controlled by the hydrologic cycle and its quantity varies worldwide. A supply of fresh water can be depleted over time.

Nearly 50 percent of the people on Earth do not have access to clean water.

Beyond our need for safe drinking water, we also need water for industry, commerce, agriculture, and residential and other needs.

Why is there a limited supply of fresh water?

Nearly 97 percent of the world’s water is salty or otherwise undrinkable.

Another 2 percent is locked in ice caps and glaciers, leaving just 1 percent for all of humanity’s needs. The demand for water continues to increase as more people withdraw more water in more ways. Whether you draw water from ground water or surface water, using too much water too fast, or contaminating it, can lead to shortages for now and later.

What is ground water?

Ground water is found beneath the Earth’s surface in the spaces between rocks and soil particles. The Earth soaks up and stores ground water much like a sponge holds water. The upper extent of ground water in the soil is the water table.

43 How is ground water replenished?

The biggest replenishing source of ground water is precipitation that soaks into the ground and reaches the water table. When deep ground water is withdrawn through wells and other means, it may require hundreds of years to be replenished. Because many bodies of surface water rely on ground water for renewal, when ground water sources are depleted, surface water quality may be affected.

What is surface water?

Surface water is any body of water we can see – streams, rivers, ponds, lakes and oceans. Because it is visible, many people think that surface water is our major source.

Actually, less than 3 percent of the Earth’s fresh water is found in streams, lakes and reservoirs. Surface water may feed into, or draw from, ground water.

What is an aquifer?

Aquifers (literally “water carries”) are underground reservoirs formed and replenished (recharged) primarily by precipitation over many centuries. Water trickles down (infiltrating and percolating) from the Earth’s surface until it meets solid rock. Two types of aquifers exist: unconfined (water table aquifer) and confined (artesian aquifer). Aquifers range from a few feet to hundreds of feet deep; their expanse ranges from a few acres to thousands of square miles.

How are aquifers useful to us?

Many people get their drinking water from aquifers. Some water stored in aquifers eventually reemerges as surface water. Water for drinking is drawn up to the surface from aquifers by wells or springs. Most U.S. aquifers are within 2,500 feet of the Earth’s surface. In many regions, however, water is pumped out of aquifers far faster than it can be replenished. Once this problem, the ground contracts and sinks. This is called subsidence – a problem many cities worldwide are facing, besides a water shortage.

What was the first legislation passed to protect our nation’s public drinking water supplies?

The Safe Drinking Water Act (SDWA), passed by Congress in 1974, was the first federal legislation to deal specifically with drinking water. Basically, this law says that we need to protect our drinking water sources for environmental, financial, social and administrative reasons, and ultimately, for “the protection and benefit of public water systems.”

What is the water (hydrologic) cycle?

The water cycle (hydrologic cycle) is an endless process by which Earth’s water is collected, purified, and circulated from the atmosphere to plans and animals, and back to the atmosphere.

44 Water evaporates from oceans and surface water into the atmosphere, where it condenses into clouds. From the clouds it falls back to Earth as precipitation, and eventually returns to oceans through a drainage system of streams and rivers. The total amount of water circulating through the water cycle never changes, as it continually shifts from gaseous to liquid and solid states.

After precipitation falls to Earth as rain, hail, sleet or snow, it meets one of several fates. Our oceans get 85 percent of all precipitation. However, some water which falls on land may run across the surface of the soil (runoff) into lakes, ponds, rivers and streams. Water that remains at the Earth’s surface is surface water. Precipitation may also soak or infiltrate into the soil. Plants absorb some of this water, and some of it seeps down through the soil until it reaches a saturated zone. Water that reaches this saturated zone is ground water.

Vaporization occurs when water molecules evaporate into water vapor from liquid water. Some water may also change directly from ice to vapor through evaporation.

This is a unique evaporation process called sublimation.

Evaporation also occurs when water enters the air as a gas. Once the vapor cools, condensation occurs and water falls to the Earth as precipitation – rain, snow, sleet, hail. As water evaporates, it leaves behind any dissolved or suspended solids, and is cleansed.

What forces drive the water cycle?

The water cycle began billions of years ago, when the Earth cooled. It is driven by the Earth’s gravity, and the heat of the sun. The sun’s heat causes the water to vaporize and then the Earth’s gravitational pull causes condensation, and eventually precipitation. The cycle will never end as long as there are plants and sunlight.

How do plants and animals fit into the water cycle?

Plants and animals, by transpiring and breathing respectively, take in water and return it to the atmosphere as vapor. Animals excrete water into the soil. A large hardwood tree can transpire as much as 40,000 gallons of water per day.

One acre of corn gives up 3,000 gallons of water daily through transpiration.

Where do we get most of our supply of water?

Our water comes from either surface water (reservoirs, lakes, ponds and rivers) or ground water (aquifers). Urban and rural residents rely on theses sources for their water supplies.

Ground water is the source of drinking water for one-half of the people in the United States. For about 95 percent of rural residents, ground water is the sole source of water.

45 Is it possible for us to make or destroy water within the water cycle?

No. Water can neither be created nor destroyed; it only changes from one form to another. Water recycles repeatedly as precipitation falls to Earth, trickles down into the ground, or evaporates into the atmosphere and returns again to Earth. Although we cannot increase the amount of water on Earth, we can increase our progress wiser management of this limited resource.

What is water quality?

The water quality of any surface or ground water varies with natural influences and human activities. Most people assume there is a universal standard for water quality – that water is either clean enough for drinking, swimming and fishing, or, if not, then it is polluted. Often water that is not clean enough for consumption and animal life is nonetheless clean enough for other purposes.

Drinking water must be of the highest quality, but water unfit to drink may be adequate for crop irrigation or a manufacturing process.

Why does water quality vary?

Water has a unique characteristic – it’s the universal solvent! Consequently, water readily gathers up iron, manganese, chlorides, sulfates, decaying organic matter and other substances as it flows downhill from higher elevation to lower sites.

The concentration of dissolved substances increases as water flows or seeps through the soil. As a result, water quality is influenced by the chemical composition of the soils it flows through. The amount of additional precipitation added to the water flow as it moves through or across the Earth also influences water quality.

All water resources contain some natural impurities. Some substances are health threats; others affect the odor, taste, or color of water harmlessly. In some areas, the sources of surface and ground water are interconnected.

Thus, changes in the quality of the surface water can affect the quality of the area’s ground water, and vice versa.

How has our knowledge of water quality changed?

Our knowledge of how clean water is depends on how well we can detect and identify the types and amounts of substances in the water. Over the past 40 years, advances in analytical techniques have enabled us to detect the presence of chemical substances in very small quantities. These new techniques have added greatly to our ability to detect how clean or polluted water is for human activity.

46 How do soil characteristics affect water quality?

The risk to water quality varies with: 

Soil texture – the composition of soil according to the proportions of its sand, silt, and clay particles. The size of soil particles has a great bearing on how easily water moves through a soil type, and how much water it can retain. Sand particles are larger than silt particles, which are larger than clay particles. But clay particle bonds are generally stronger than particles of silt and sand. A large percentage of clay in the soil means slower water flow than soil with a larger percentage of silt and sand.



Soil permeability – the capacity of porous rock, sediment or soil to allow water (or any fluid) to pass through it. Shape, size, and arrangements of particles influence the pathway and rate of fluid movement through soil.



Soil organic matter – the decomposed remains of plants and animals.

Organic matter greatly affects both the physical and chemical properties of soil, thus influencing how much water the soil can hold before downward movement or runoff occurs. When organic matter is plentiful, the soil’s fertility, water infiltration rate, and storage capacity improves.

What are some usual human induced ground water contaminants?

The potential sources of human induced water contamination span every facet of social, agricultural and industrial activity. Some common ground water contaminants include: inorganic salts, pesticides, nitrates, seawater, gasoline, solvents and other organic chemicals.

What are some human activities that increase the risk for ground water contamination?

Septic tanks and systems, municipal landfills, underground fuel tanks, mining operations, hazardous waste disposal sites, improper agricultural chemical application, municipal waster water systems, unpaved animal feedlots, animal manure and road deicing are some of humanity’s major contributions to ground water pollution. But frequently, public attention is drawn to agrichemicals (pesticides, nutrients/fertilizers).

What do agrichemicals vary in their potential to become contaminants?

Generally, three key characteristics influence an agrichemical’s potential for ground water contamination: persistence, solubility, and density.

47

Persistence – the ability of a chemical to remain toxic. This toxicity is usually measured in terms of half-life. Half-life refers to the time it takes for half of the applied chemical to be transformed or degraded into a harmless by-product.

The more persistent ones are more likely to reach ground water eventually.

Solubility – is the ability of a chemical to dissolve in water.

Some contaminants such as salts readily dissolve in water, while others, such as many organic chemicals, are relatively insoluble. Chemicals vary greatly in their water solubility; the greater their water solubility, the greater their potential for movement into ground water.

Density – insoluble chemicals which are lighter than water (of less density) will float on top of water in an aquifer. They can spread through a large area as a thin film. On the other hand, insoluble chemicals, which are heavier than water, often sink to the bottom of an aquifer. Water in an aquifer typically moves only 100 feet per year. Because ground water cannot be “stirred up,” very little mixing or dispersion of contaminants occurs. Subsequently, dense-than-water chemicals that sink and linger in ground water pose a long-term threat as contaminants.

What are point and non-point sources of water pollution?

Polluting substances can enter surface and ground water from two very different sources: point sources (readily identifiable sites, such as a discharge pipe or ditch) and non-point sources (over a large areas from unspecified locations). Agricultural pesticides, fertilizers, petroleum products and animal wastes can contribute to non-point source water contamination.

When agrichemicals fail to decompose into harmless chemicals soon after application, there is a risk that they will become sources of non-point water pollution. Such pollution occurs through runoff, soil erosion or by leaching into the soil.

How can people applying chemicals help reduce water contamination?

By far, the most important than people using chemicals can do, is to strictly follow label instructions. Even the most toxic agrichemicals present little if any risk to humans when used according to registered label directions, and with good agricultural production practices.

Can we encourage people applying agrichemicals to do anything else to protect our water resources?

By observing other simple precautions, people applying chemicals can reduce the risk of these chemicals reaching ground water.

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Among the precautions are: proper use of accurately calibrated spraying equipment; prevention of back-siphoning and spills into water sources; mixing pesticides away from drinking water sources; proper pesticides and container disposal; proper timing and control of irrigation following rainfall; and proper well construction and location.

How should we handle empty pesticide containers?

Check the label first for proper disposal recommendations. Generally, all containers should be triple-rinsed and the rinse poured into the spray tank before disposal. Methods of disposing of unused pesticides are also important.

Empty bags or boxes containing unused pesticides should be disposed of in a properly authorized landfill; or incinerated.

What land management practices could also help prevent water pollution?

Food and fiber producers can be encouraged to use erosion control practices.

These practices include conservation tillage (leaving 30 percent or more of the soil surfaces covered with a crop residue – leaves, stems or stalks – between harvest and planting) and conservation cropping (crop rotations, contour cropping, and strip cropping).

Besides reducing soil erosion from water and wind, crop residues help keep nutrients and pesticides from washing off the field. Currently, conservation tillage systems are used on 109.8 million acres, or 37 percent, of the 294.6 million acres of crop land planted annually in the United States. Farmers using conservation tillage make fewer trips through fields – saving money, time, fuel, labor and wear on machinery.

Is animal manure a potential water contaminant?

It can be. Runoff from manure-covered areas can be contributing pollutants to nearby rivers and lakes. Animal manure has organic matter, plant nutrients, salts, and pathogenic microorganisms (causing or capable of causing disease) which can damage water quality. The sheer volume of manure generated presents a water quality challenge for livestock producers.

A single dairy cow produces about 21 tons of manure in a year. Imagine, then, a dairy farm with 100 cows, which produces up to 2100 tons of manure each year!

How can microorganisms from animals cause problems for our water resources?

Microorganisms from animal or human intestinal tracts thrive in fecal waste.

Water that contains fecal waste can cause disease. Human and animal fecal water can be a source of harmful viruses and bacteria.

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When such microorganisms enter surface or ground water, the water becomes instantly unhealthy, especially for drinking purposes.

Surface water containing microorganisms must be “treated” for such uses as drinking and cooking. Contaminated drinking water may sometimes have peculiar tastes, odors, or visible particles.

However, some harmful contaminants in water are difficult to detect. Public water treatment systems generally use the following process to clean water: (1) aeration – air (oxygen) is added to the water; (2) coagulation – dirt and suspended particles are processed then removed; (3) sedimentation – gravity pulls coagulated particles to the bottom of a tank; (4) filtration – different filters remove impurities; and (5) disinfection – chlorine is usually added to the water to kill any remaining organisms that may be harmful.

What else can affect microorganism contamination of our ground water resources?

Soil has physical properties that are especially favorable to entry of harmful microorganisms into ground water. Highly porous earth (coarse, sandy soils, fractured rock) are excellent pathways for the entry of microorganisms into ground water. When the soil has smaller particles, such as clay or silt, it provides fewer chances for microorganisms to enter the water table.

Although fecal microorganisms can filter through the soil, soil-climate conditions usually destroy them. Harmful microorganisms can also enter ground water from poorly designed wells, which allow surface water to seep downward alongside the well.

Domestic waste systems such as outhouses, poorly designed septic tank systems, or systems too close to wells also increase risks to drinking water contamination by microorganisms.

What health problems can waters contaminated by fecal waste cause?

Among other diseases, water contaminated by fecal waste is likely to cause gastrointestinal illness (diarrhea, fatigue, cramps, etc.), hepatitis A, meningitis, ulcers, typhoid fever, and cholera.

Can animal manure be useful to replenish soil nutrients?

The use of animal manure to replenish soil nutrients is often a highly controversial issue. Properly handled and used, manure is an asset. Manure spread on land restores nutrients and replaces much commercial fertilizer.

Animal manure also increases soil fertility and water’s holding capacity by adding organic matter to the soil. It thus improves crop production and farm profitability.

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By using the nutrients in manure, farmers can reduce their purchases of commercial fertilizer and their crop production costs.

Is there anything that we can do once ground water is contaminated?

Yes! Fortunately, today we have the technology to remove many contaminants that degrade water quality. Nonetheless, once water is contaminated cleanup options are limited, difficult, time-consuming, and extremely expensive. The water cycle serve as nature’s method of naturally cleaning or recycling waster, but that process takes an enormous amount of time. Clearly, the best option for ground water protection points to prevention. However, such prevention largely depends on wise management techniques.

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WAT’ER YOU DRINKING? What to Expect Participants will discover the percentage of water on earth that is capable of supporting human activities.

Materials Needed  Paper  Mathematical compass  Scissors  Green, yellow and blue markers or crayons  Paste  Pencils Getting Ready  Review Splish Splash background information and discuss with the group. 

Have youth take the Water Quality pre-test found in What’s the Score?

Listen Up! There are many natural resources on earth that are important to our everyday lives. The land on which we depend for growing food and fiber is one such resource. Another is water, which is the essence of life. Demand for use of both of these important resources is increasing as our population continues to increase. It took from the beginning of time to 1950 for the world’s population to reach 2.5 billion people. At the beginning of a new century water is now even more precious, as the world’s population has reached over six billion people! Projections are that by the 2025 there will be 8.4 billion people on earth. Who can we depend on to be wise stewards of the land, and where will we get the water we need to sustain life?

In this activity, you will draw a pie chart to illustrate the percentage of drinking water found on the earth.

Activity 1. Explain that each student will use a compass to draw a circle with a six inch diameter. Mark the circle’s center with a small dot.

2. Use a pair of scissors to carefully cut around the edge of the circle. Tell the youth that they will use the circle to make a pie chart that will illustrate the amount of water found on earth.

3. Start folding the circle in half, and then into quarters.

52 4. Now fold the quarters in half to form eighths.

5. Fold the eighths in half to make sixteenths, and then fold them once more into thirty-seconds.

6. Unfold the circle and locate one of the thirty-second slices.

7. Explain that they will use the fold lines as a guide to outline a 1/32 slice with their ruler and pencil. Color everything but this slice of the pie green. This green portion represents approximately 97 percent of the world’s water that is salty or otherwise undrinkable.

8. Next, ask them to look at the outlined 1/32 slice. Divide this slice into three small slice of equal size. They are very thin, aren’t they? Two of these slices represent the two percent of earth’s water that is locked in ice caps and glaciers. Color this portion yellow. The final small slice represents the one percent of earth’s water that is available for all of humanity’s needs. Color this portion blue.

9. Paste the pie charts on the top half of a plain sheet of paper.

10. On the bottom half, ask everyone to write a letter to people on another planet explaining how much usable water is available on earth.

Share  What did you learn about using fractions? 

What did you learn about the quantity of drinkable water you did not know before?



What was the most difficult part of this activity? Easiest?

Process  What does dividing the circle into portions tell you? 

Discuss whether or not you think there is enough water for all of the world’s population to drink.



Which is most important – water quality or water quantity? Why?

Generalize  What is the difference between renewable and non-renewable resources? 

When is it important to divide something into smaller portions of equal size?



53 In what other ways do people use percentages to compare relationships?

Apply  Who is responsible for taking care of other natural resources on earth? 

If you wanted to start a water conservation program at your school, how would you begin?



What other tools can you use to draw a circle and divide it into slices of varying proportions?



How will you apply what you have learned in this activity in your Down-toEarth garden?

Want To Do More?

Have the participants:  Make another pie chart and illustrate the 1/32 of the earth that supplies most of our food and fiber crops. Then, illustrate the 3/100 of one percent of the earth’s surface covered with usable water. 

Visit a water treatment and wastewater treatment facility to meet and hear from people who are responsible for taking care of water quality.



Find out about a career in hydrology.

Test Your Knowledge Have participants take the Water Quality post-test found in What’s the Score?

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SAFETY Objective: To provide students with background information on the safe handling of farm and garden chemicals.

After reviewing this unit, the learner will be able to:  explain why it is important to handle chemicals carefully  list ways to know what chemicals are most dangerous if misused  describe correct methods for handling chemicals  explain what protective clothing is important  describe appropriate protective clothing  list ways to handle contaminated clothing Pesticides are used by farmers and gardeners to reduce damage from insects, weeds and diseases. As helpful as they can be, pesticides also can be harmful to humans and the environment if precautions are not taken when using them.

Most pesticides accidents occur when users are careless, or unaware of proper procedures.

Safety. What makes agricultural chemicals harmful to humans?

Contact with certain chemicals can increase the risk of illness and injury, and sometimes death. Danger depends on the toxicity of the chemical. Most of the time, pesticide poisoning is temporary, but it can cause permanent damage.

Individuals exposed to large amounts of pesticides may develop flu-like symptoms, or develop a rash in the area where the chemical came in contact with the skin. It is important to know the potential hazards of chemicals.

Safety. How do chemicals enter the body?

Chemicals can enter the body through the mouth (orally), the eyes and skin (dermally), or lungs (through inhalation). It is important that users know which exposure present a danger with the chemical they are using. For someone in normal clothing, areas of skin exposed are the hands, arms and face. Usually, the mixing and preparation of farm chemicals is not as hazardous as the process of applying chemicals to crops, but care and caution are nonetheless necessary in preparating chemicals as well as applying them.

Safety. Where can important safety information about chemicals be found?

The label on chemical containers is an important source of information necessary for safe chemical handling. The user should read these labels carefully to learn of the chemical’s possible hazards, such as flammability, corrosiveness and toxicity. Labels will explain dangers and recommend

precautionary steps. With this information, users can take precautionary measures to protect themselves.

55 Safety. What clothing precautions should be taken when working with chemicals?

Even though most planting is done during the hot summer months, it is desirable to try to cover the body as much as possible when applying chemicals. There are certain fabrics, such as DuPont’s Tyvek Ž, which are resistant to chemicals absorption. These fabrics provide a great deal of protection. Many of the garments made of chemical resistant fabrics are disposable, and should be discarded after one use.

If it is not possible to wear outfits made of these fabrics, however, there are nonetheless other precautions that should be observed before using chemicals.

One precaution is wearing long, tightly woven pants and a long-sleeve shirt.

Avoid cotton as much as possible, because it is an absorbent fabric which might retain dangerous chemicals. A cap, preferable a hard hat, is essential.

Gloves (latex or rubberized) are needed to protect the hands. Wearing cotton or leather gloves, due to their absorbent nature, can be as dangerous as wearing no gloves at all. Cover the feet with rubberized boots. Goggles or some type of protective glasses are necessary for eye protection.

How the clothing is worn is as important as what is worn. As a rule, shirt sleeves should be worn on the outside of gloves, to prevent chemicals from entering the gloves at the cuff. However, when spraying overhead, the sleeves need to be worn inside the gloves. Pant legs should always be worn on the outside of the boots.

Some chemicals may be harmful if inhaled. Therefore, a respirator that filters the chemical from the air you breathe may be necessary.

Safety. How should clothing be handled when the chemical application is finished?

Even when the work is done and the chemicals are securely stored, the issue of safety lingers until all clothing is properly cleaned, or disposed of when necessary. Before removing gloves, first wash them with detergent and water to prevent skin from coming in contact with contaminated gloves. After they are removed, gloves should be checked for leaks by filling them with water and then squeezing them. Any leaking glove should be discarded. The same procedure should be followed for cleaning rubberized boots. If disposable clothing is used, follow the manufacturer’s recommendations for disposal.

Do not wash clothing contaminated by chemicals with the family laundry.

Contaminated clothing must be laundered separately, in the hottest water that is still safe for the fabric. Use chlorine bleach, if possible.

Pre-rinsing the garments before putting them into the washing machine will help remove some of the chemical’s residue.

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AMAZING FACTS A national pesticide use survey found that nearly 62 percent of U.S. households store between six and ten pesticide products in their homes.

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SKIN DEEP What to Expect Participants will discover that some clothing fabrics provide only minimal protection when applying pesticides.

Materials Needed One set for each group:  4 clear plastic cups  8 brown paper towels, cut into 5-inch squares  5-inch squares of each of the following fabrics: o 50% cotton/50% polyester blend knit (t-shirt type fabric) o 100% cotton knit (t-shirt type fabric) o 100% cotton denim (blue jean fabric)  Rubber bands  Spray bottles filled with water  Ruler LIFE SKILLS  Decision making  Keeping records  Cooperation  Teamwork  Personal safety PROCESS SKILLS  Acquiring, processing and interpreting data  Experimenting  Analyzing investigation Getting Ready  Review You’re Safe! background information and discuss with the group.  Have participants take the Safety pre-test found in What’s the Score?

Listen Up! Pesticides are designed to kill so it is wise to handle all pesticides with caution!

A common means of pesticide poisoning is through skin contact. It is very important to keep pesticides off your body whether the pesticide is a liquid spray or granular (solid) chemical. A small amount of a pesticide on your skin

may result in a burn or rash. Once a pesticide is absorbed through the skin, it quickly moves through the bloodstream into other parts of the body.

58 Skin protection is one important reason for clothing. The skin covering the human body is divided into two layers: an outer layer (epidermis), and the inner layer (dermis). Blood vessels are abundant in the dermis but there are none in the epidermis. Moreover, different parts of your body absorb pesticides at different rates.

Anyone who handles, mixes, or applies any pesticide – even those considered “safe” – should wear protective clothing! Manufacturers’ precautionary statements on the chemicals’ labels tell the type of protective covering that will reduce exposure to the pesticide. Usually, underclothing, a long-sleeved shirt, long pants, a hat with a brim, socks, and chemically resistant gloves and boots are essential. Coveralls, a chemically resistant apron, a face shield, and goggles or respirator may be necessary for persons who are mixing and loading pesticides.

In this activity, you will explore the absorbency of various fabrics that may be worn while applying pesticides.

Activity 1. Divide the group into smaller teams of three or four people.

2. Give each team:  4 cups  1 square of each of the fabrics  8 brown paper towel squares  1 spray bottle filled with water  4 rubber bands 3. Place one paper towel on top of another, forming two layers (skin). Drape them over the tops of each cup. On one cup, secure the towels with a rubber band around the rim, as tight as possible to form a “drum.” This will represent unprotected skin.

4. Cover the top of the next cup with three layers – two paper towels and the square of 50% polyester/50% cotton fabric to cover the “skin.” Secure with a rubber band. Repeat this procedure with the 100% cotton knit fabric and the 100% cotton denim fabric. These will represent skin covered by three different types of clothing.

5. Turn the “skin” cup on its’ side. One person will hold the cup, use the sprayer and count the number of sprays. Another person will stand on the opposite side, close enough to the cup to observe and record what happens to the bottom layer.

59 The sprayers will hold the tip of the spray nozzle six inches away from the top, and begin to spray the water (pesticide substitute). When the bottom layer of paper is completely wet, the observer says “STOP!” The sprayer will record the number of sprays that it took to reach this point.

6. Repeat Step 5 with each of the other cups. Record the number of sprays (data) and graph the results.

Share  What happened to the “skin” when the outer fabrics were saturated with the “pesticide?” 

What did you learn about protective clothing and pesticide application?



How did you measure the distance between the spray nozzle and the cups?

Process  What can you conclude by comparing the observations and data that were recorded from each experiment? 

Explain why the experiment using “skin” only became saturated the quickest.



Why is it important to take standard (similar) measurements in an experiment?

Generalize  What makes a person feel safe? 

What else provides protection and for what reason?



Why is it important to have plenty of safety information?

Apply  How will you use what you learned in this activity? 

How will you decide what type of protection is needed to keep you safe in the future?



In what other areas will you use observations, experimentation and drawing conclusions?



How will you apply what you have learned in this activity in your Down-toEarth garden?

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Share Have the youth: 

Prepare a report on the use of chemicals in a garden.



Visit a garden or farm center and develop a list of the protective clothing and equipment they sell.



Explore a career in textile technology.

Test Your Knowledge  Have youth take the Safety post-test found in What’s the Score?

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